This page lists the allowed extension values for the rel="" attribute in HTML5. You may add your own values to this list, which makes them legal HTML5 rel values. We ask that you try to avoid redundancy; if someone has already defined a value that does roughly what you want, please reuse it. Note that rel tokens are ASCII-lowercase before comparison against canonical value, so the canonical values should be listed without uppercase ASCII letters.

Keyword

Effect on...

Brief description

Link to more details

Synonyms

Status

link

a and area

accessibility

hyperlink

hyperlink

The linked document contains accessibility information for the linking document.

Robots (e.g., search engines) should treat the document containing the tag as a minor variation of the linked document, which may result in the removal of the former from a web index and in the consolidation of its quality signals in the latter.

More than one domain may have largely similar or identical content but only one of the domains should be indexed for search engines. E.g., a company may have short and long domain names for the same content.

Where the canonical value should point to a group of pages, but the link can point to only one page, the group of pages can be clarified by choosing the first page in the group and assigning the URL for this rel link.

For security against traffic theft, rev must be meaningless.
This is only shorthand for providing two link elements, one on the noncanonical page to a "canonical" page and the other on the canonical page to the "first" page of the group.
Where the group of pages corresponds to a subdirectory and a canonical URL value can point to the subdirectory resulting in a user arriving at the subdirectory's index page which is part of the group, this shorthand is unnecessary and one rel="canonical" will suffice.

Both bare and www-prefixed domain names usually direct to the same site. Especially when external links to a site vary in the form used, search engine indexing concentrated on only one domain form may raise its credibility. The rel value is the form preferred for indexing, e.g., rel="http://example.net". Nothing to the right of the top-level domain is needed.

Indicates a same page jump from the current fragment to another fragment. (E.g. sometimes online newspapers insert direct text saying "article continues below the image/advert" - they could instead use "jump" link. Ultimately, it indicates a page internal link.)

The linked document contains a version of the current document in an alternative language. "[ISO 639-1 code]" is replaced with the appropriate ISO 639-1 language code. The ISO 639-1 code is used when the browser (or other user agent) wants to display either the full name of the language or a flag, as a visual aid for the end user.

Proposal

lang-orig-[ISO 639-1 code]

hyperlink

hyperlink

The linked document contains a version of the current document in the language the document was originally written in. "[ISO 639-1 code]" is replaced with the appropriate ISO 639-1 language code. The ISO 639-1 code is used when the browser (or other user agent) wants to display either the full name of the language or a flag, as a visual aid for the end user.

Proposal

last

See HTML5

license

See HTML5

logout

external resource

not allowed

The linked document provides a resource for the UA to request when all currently open documents of the same "group" are closed (to facilitate logging out the current user).

Denies prefetching (not fetching) as a cost-control option for website owners, especially where pages are dynamic, leading to prefetching of wrong and useless pages.

The link provides a per-page denial whereas a and area provide a per-element denial.
For link, attributes rel="noprefetch" denies prefetching of the page at the href URL and rev="noprefetch" denies prefetching of the page bearing the link.
For a and area, rel is as above and rev is meaningless.

The referenced document is recommended for printing, even though the referent document is capable of being printed and both documents are of the same type, medium, and language. A typical case is where content spread over multiple pages is also available on a single page that is more convenient to print.

This is semantically more specific than "canonical" and "alternate". Where type, medium, and/or language differ, consider "alternate"; where any of them differ but the purpose is printing, consider applying both values.

The referenced document offers one or more pronunciations to aid text-to-speech (TTS) synthesis software, especially for unusual and new words. The referenced document can be in any format that supports the functionality, including *.pls.

The linked document is the page/email that has been translation source for the current document. It also indicates that the current document is a translation and not an original work.

Proposal

translator

hyperlink

hyperlink

The linked document is the page/email an agent (people or firm or...) responsible for the translation of the page. It also indicates that the current page is a translation of an other document, which should be linked through a rel="translatedfrom".

Proposal

up

See HTML5

webmaster

hyperlink

hyperlink

The linked document is the page/email an agent (people or firm or...) available for requests about the content of the page.

The "Effect on... link" column must either say "not allowed" if the rel value is not allowed on <link> elements, "hyperlink" if the rel value creates a hyperlink, or "external resource" if the rel value creates a link to an external resource.

The "Effect on... a and area" column must either say "not allowed" or "hyperlink".

For the "Status" section to be changed to "Accepted", the proposed keyword must either have been through the Microformats process, and been approved by the Microformats community; or must be defined by a W3C specification in the Candidate Recommendation or Recommendation state. If it fails to go through this process, it is "Rejected".